Extends DefaultTravesablePanel with the ability to skip to the next panel.

If there are wizard call backs, and the traversable context
has UIConstants.FIRST_NON_DEFAULT_PANEL defined;
If this is not the FIRST_NON_DEFAULT_PANEL as defined by the PANEL_ID,
skip to the next panel.

If this is the FIRST_NON_DEFAULT_PANEL,
null UIConstants.FIRST_NON_DEFAULT_PANEL so that we can now traverse
back to the previous panels.